Abstract Comprehensive exposure assessment in the field of occupational health has been limited, historically, by a combination of technological, financial, and human factors. The cost and complexity of personal sampling technology limits a single industrial hygienist (IH) to making, at most, about 10 measurements of personal airborne exposure each day. Many hygienists can work together to produce a larger exposure dataset; however, the cost to assess exposures for every worker in a facility is exorbitant under the current paradigm. These limitations hinder our ability to identify workers at risk of overexposure; they also lead to imprecise effect estimates in occupational epidemiology. Collectively, these limitations lead to greater risks of poor health outcomes among workers. This project seeks to develop new technologic and methodologic approaches for assessing worker exposure to occupational air pollutants. We will develop a wearable exposure monitor for aerosol and vapor hazards that is immediately deployable ?out of the box? with minimal user training. Further, the monitor will be designed to take reference-quality measurements of tens to potentially hundreds of different airborne compounds. We also seek to transform the practice of industrial hygiene by further leveraging support and participation of the workers themselves through a citizen-science approach to hazard identification and exposure assessment. Successful completion of this research will enable dramatically greater sample sizes for personal exposure measurements in the workplace, which, in turn, will promote more better professional judgement, more efficient hazard control, more effective epidemiology, and improved worker health. A second goal is to demonstrate the potential for citizen science to improve worker comprehension of and engagement in workplace safety culture. The project has two aims. The first is to develop a simple, inexpensive, ?smart? sampling device for comprehensive assessment of personal exposures to aerosol and vapor hazards. The device will be small and easy to deploy and wear while containing quality-assurance features necessary to meet the performance of accepted standard reference methods (active flow control, fault monitoring, user compliance). The second aim is to conduct a series of field deployments to evaluate whether the new technology, when used with a citizen science approach, can promote better engagement in and knowledge of workplace health and safety among workers, organizations, and industrial hygienists. We hypothesize that the citizen-science approach will change worker- and organizational-level attitudes and behaviors relevant to occupational hazard assessment and mitigation. We also hypothesize that industrial hygienists will improve their ability to accurately assign workers to exposure control categories, when presented with the comprehensive exposure data we generate. Successful completion of this work will validate a new technology for workplace hazard assessment while demonstrating the utility of a citizen science approach to increase knowledge and awareness of health and safety in the workplace.